// -*- mode: c++; c-basic-offset: 2; -*-

#include "common.hh"
#include "test.hh"

#include "observers.hh"

namespace {

bool test_sanity() {
  Observers<int> obs;
  ASSERT_EQ(false, obs.notify().has_next());
  obs.insert(1);
  auto it = obs.notify();
  ASSERT_EQ(true, it.has_next());
  ASSERT_EQ(1, it.next());
  ASSERT_EQ(false, it.has_next());
  obs.erase(2);
  it = obs.notify();
  ASSERT_EQ(true, it.has_next());
  ASSERT_EQ(1, it.next());
  obs.erase(1);
  ASSERT_EQ(false, obs.notify().has_next());
  return true;
}

bool test_insert() {
  Observers<int> obs;
  auto it = obs.notify();
  ASSERT_EQ(false, it.has_next());
  obs.insert(1);
  ASSERT_EQ(true, it.has_next());
  ASSERT_EQ(1, it.next());
  obs.insert(2);
  ASSERT_EQ(false, it.has_next());
  it = obs.notify();
  ASSERT_EQ(true, it.has_next());
  int other;
  switch (it.next()) {
  case 1:
    other = 2;
    break;
  case 2:
    other = 1;
    break;
  default:
    ASSERT_TRUE(false);
  }
  ASSERT_EQ(true, it.has_next());
  ASSERT_EQ(other, it.next());
  return true;
}

bool test_erase() {
  Observers<int> obs;
  auto it = obs.notify();
  ASSERT_EQ(false, it.has_next());
  obs.insert(1);
  ASSERT_EQ(true, it.has_next());
  ASSERT_EQ(1, it.next());
  ASSERT_EQ(false, it.has_next());
  obs.erase(1);
  auto it2 = obs.notify();
  ASSERT_EQ(false, it2.has_next());
  it = it2;

  obs.insert(4);
  obs.insert(3);
  obs.insert(2);
  it = obs.notify();
  ASSERT_EQ(true, it.has_next());
  ASSERT_EQ(2, it.next());
  obs.erase(2);
  it2 = obs.notify();
  ASSERT_EQ(true, it2.has_next());
  ASSERT_EQ(3, it2.next());
  obs.erase(3);
  ASSERT_EQ(true, it.has_next());
  ASSERT_EQ(4, it.next());
  ASSERT_EQ(true, it2.has_next());
  ASSERT_EQ(4, it2.next());

  return true;
}

}  // namespace

int main(void) {
  BEFORE;
  RUN(test_sanity());
  RUN(test_insert());
  RUN(test_erase());
  AFTER;
}